motors

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blt

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230/460v 3 phase name plate on motors. Building power is 208/480 how critical is this for efficiency obviously, as well as having 480v serving a 460v motor or 208 serving a 230v motor. People have said not a problem. Expierience tells me less life of a motor.

[ June 30, 2005, 06:06 PM: Message edited by: blt ]
 
Re: motors

A 460 volt marked motor is fine on 480 volt systems.

As a mater of fact I am not sure you will find motors marked 480 volt.
 
Re: motors

Nominal system supply voltages like transformers and generators are (and have been for 50yrs) 120, 208, 240, 480, and 600V.

By convention utilization equipment, like motors, are rated 115, 200, 230, 460, and 575V. But, other equipment, like heaters, are rated at nominal voltages.

So, 460V motors are intended to be fed from 480V supplies. 230V motors are not always capable of being fed from a 208V system, however some manufacuters do allow it.

The more heavily loaded the motor and the less regulated the source the more likely you are to have future problems if you use a standard 230V motor at 208V.
 
Re: motors

BLT
You should be fine with the 480 v to that motor but the 208v to it could take the life out of it. If you check your 208 voltage in your building it might be more like 213 volts that would help you. But I would be very carefully using the lower voltage for your 230v motor. Sorry I couldn't help you that much.
Jim
 
Re: motors

The nema nameplte rating on a 23/460 volt motor is + or - 10% of the rated nameplate voltage at full load. In other words you have a 230 volt motor les 23 volts and you have a motor that according to nema will operate at rated load on 207 volts. I owned a motor shop for 17 years and we always advised customer not to do it unless the motor was tri rated. IE 208/230-460. Many manufacturs do rate thier motors this way especially fractional hp 56 frames from 1/4 thru 2 hp. Baldor is a good example of this as well as doerr and leeson.I sold lincoln motors for years and would never ever have used them on 208 volts. We always sold a 200/440 volt motor for this.Just my 2 c worht. Joe, Another thing to consider is load. If you do not fully load the motor say it operating at 75% load then the lower voltage is not as crirical. The important thing to remeber when checking units like this is to put them under normal laod condition and check the current draw. You cannot hurt the motor under any circumstances if you NEVER exceed the nameplate amps. Amps create heat and heat kills motors. It lets the smoke out and thats bad. Contain the smoke and you are good to go.

[ July 01, 2005, 01:11 AM: Message edited by: stew ]
 
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